Ever since automobiles have been driven with headlgiths at night, there has been a problem of how to reduce the glare of oncoming headlights when meeting another automobile. For example, U.S. Pat. Nos. 1,067,793 filed by Barr in 1911 and 1,239,691 filed by Howe in 1915 provide goggles or eyeglasses with lenses having partially shaded or opaque areas intended to block headlight glare. Numerous variation of eyeglasses and shades have been devised for anti-glare use in night driving. Exemplary of such variations are the eyeglasses shown in U.S. Pat. Nos. 1,643,509 to Moran, 1,676,760 to Wilson, 1,706,429 to Willard, 1,723,474 to Esleck, 2,230,009 to Ordorica, 2,358,602 to Snyder, 2,639,430 to Gale, 2,699,093 to Auwarter, 2,875,670 to Thorton, 3,199,114 to Malifaud, 3,512,880 to Alexander et al., 3,6664,733 to Kalkowski and 4,338,003 to Adrian. The disclosures of the above patents are incorporated herein by reference.
In my copending applcation Ser. No. 049,706 field of even date with this application and entitled "Anti-glare Visor System" I have described and claimed anti-glare visor systems for vehicles which can be used to screen headlight glare at night. The disclosure of said copending application is incorporated herein by reference.
Of the numerous variations of anit-glare eyeglasses in the prior art, none has satisfactorily solved the problem of headlight glare and each design contains certain deficiencies and problems in actual use. For example, some are too restrictive, block too much vision and are not adaptable in actual use to bvariabel road conditions, as in Adrian, cited above. Others reduce vision in the primary field of vision, such as in Kalkowski. Moreover, the problem of headlight glare in rear view mirrors has not been addressed by the prior art with respect to anti-glare eyeglasses to any significant extent. Therefore, it is an object of this invention to provide anti-glare eyeglasses and related articles for effective elimination or reduction of headlight glare.
I have observed that during night driving the driver's eyes are adapted to low light levels and are sensitive to bright light. It is believed that the pupils of the eyes are open wide and the retinas are adapted to viewing objects in dim light and are very sensitive to bright light. When exposed to a bright light, suddenly or momentarily, like an on-coming headlight, the brigh light causes momentary or temporary "blindness" in at least that part of the eye and frequently in most or all of the eye, particularly when the ambient light conditions are very low and the bright light is very bright. It is believed that this momentary or temporary "blindness" is caused by the pupil closing and by over exposure of the retina while the eye is in a sensitised condition due to the low ambient light conditions. Recovery from this temporary "blindness" and a return to normal sight for the existing conditions can take a certain period of time before road conditions ahead of the driver can be seen again clearly enough. This results in a very dangerous condition when a driver of a motor vehicle is momentarily or temporarily "blinded" by headlight glare and cannot see normally for such a period of time, particularly when the driver is traveling at a high rate of speed. This momentary or temporary "blindness" can be caused not only from the glare from headlights of on-coming vehicles but also and independently from the glare from headlight reflected in rear view mirrors from vehicles following the driver. Therefore, it is an object of this invention to provide effective shielding in either or both cases, that is of both on-coming headlight glare and/or the glare of headlights reflected in rear view mirrors.